Sandals and Method of Making Same

The field of this invention is footwear, particularly of the type relating to sandals and methods for making same.

Prior art sandals include those such as disclosed in U.S. Pat. Nos. 3,404,469; 3,352,033; 2,761,224; 2,669,036 and 2,239,471.

Some of the difficulties encountered in sandals generally include straps that may become easily detached from the sole of the shoe becuase of inadequate securing members, sandals that are not resistant to water, and straps that may potentially cause chafing and/or binding against the foot.

The present invention provides a new and improved sandal, and method for making same, the sandal having a laminated platform conforming substantially to the shape of the sole of the foot and formed of at least two layers, stirrup strap means mounted with the laminated platform for securing the laminated platform to the foot with the stirrup strap means having a loop extending through the upper layer of the laminated platform and toe securing means mounted adjacent the toe end of the laminated platform with the stirrup strap means and adapted to be positioned between adjacent toes of the foot for securing the stirrup strap means adjacent the toe end of the laminated platform to the foot.

FIG. 1 is an oblique view of the sandals of the present invention as completely assembled;

FIG. 2 is an exploded, isometric view of the sandal of the present invention;

FIG. 3 is a side view, partially in section, of the sandal of the present invention;

FIG. 4 is a side view of the sandal of the present invention, partially in section, and completely assembled, as fitted to the foot and showing flexing of the toe securing means;

FIG. 5A is a front view of the connector means of the sandal of the present invention;

FIG. 5B is a side view of the connector means of the sandal of the present invention;

FIG. 6A is a side view of the toe securing means of the sandal of the present invention;

FIG. 6B is a front view of the toe securing means of the sandal of the present invention; and,

FIG. 6C is a side view of the toe securing means of the sandal of the present invention in its overlapped position.

In the drawings, the letter S designates the sandal of the present invention. The sandal S includes a laminated platform P having stirrup strap means A mounted with the platform P and toe securing means T for securing the stirrup strap means A with the platform P.

The sandal S includes a laminated platform P having an upper layer 10 and a lower layer 12. Preferably, the upper layer 10 is of a vinyl foam such as that marketed under the name "Rubatex" vinyl foam R-326-V, however, other materials, such as polyethylene or rubber foams, may be used. Preferably, the lower layer 12 is of a neoprene foam, however, other materials may be used. It is preferred that the lower layer 12 be of a more durable higher durometer material than the upper layer 10 to provide a wear-resistant sandal sole to prolong the life of the sandal S of the present invention. Further, it is preferred that the upper layer 10 be of a vinyl foam inasmuch as typically, such vinyl foams are softer, of a lower durometer, and more resilient than the more durable, high durometer, long lasting neoprene foam. The vinyl foam of the upper layer 10 is a comfortable, soft material to be fitted adjacent the foot F of a wearer of the sandals S.

Preferably, the laminated platform P is of an approximate thickness of one inch, but it is intended that the platform P not be limited only to thickness of one inch but also to include thickness both greater and lesser than such thickness. Still further, the laminated platform P may include further intermediate layers between the upper layer 10 and the lower layer 12 to increase the overall thickness of the sandal S and/or softness of the sandal S. For example, by forming the laminated platform P having a third layer (not shown) therebetween upper layer 10 and lower layer 12 of a vinyl foam having a density less than that of the upper layer 10, a typically very soft, light-weight material is sandwiched between the upper layer 10 and lower layer 12. The results in the laminated platform P of the sandal S being of a greater thickness but also of greater softness to the foot F of the wearer. Typically, such soft intermediate layers are subject to high rates of deterioration should such soft material be used as a upper layer 10 or a lower layer 12. However, by sandwiching such soft intermediate layers between layers 10, 12, such soft materials are protected from excessive wear while providing comfort for the foot F of the wearer.

The platform P is formed to conform substantially with the shape of the sole of the foot F as is upper layer 10 and lower layer 12. The upper layer 10 has an upper surface 10a and a lower surface 10b and further includes a toe end 10c adjacent the toes 14 of the foot F and a heel end 10d adjacent the heel 16 of the foot F. Similarly, the lower layer 12 has an upper surface 12a and a lower surface 12b and a toe end 12c adjacent the toes 14 of the foot F and a heel end 12d adjacent the heel 16 of the foot F. Preferably, a plurality of slits 18 are formed in the lower surface 12b of the lower layer 12. The slits 18 preferably are formed substantially perpendicular to the longitudinal axis 26 (FIG. 1) of the platform P and extend across the entire width of the second layer 12 but, may be formed in any other desired direction and/or crossing pattern. The slits 18 help prevent slippage upon wet, slick surface and further promote flexible bending of the sandal S as described more fully hereinbelow. Further, the slits 18 help prevent formation of a vacuum therebetween the lower surface 12b of the lower layer 12 and the surface which is being walked upon.

A toe opening 20 is formed in the upper layer 10 adjacent the toe end 10c extending therebetween upper surface 10a and lower surface 10b of the upper layer 10. Heel openings 22, 24 are formed adjacent the heel end 10d of the upper layer 10 and extend between the upper surface 10a and lower surface 1b of the upper layer 10. Preferably, the heel openings 22, 24 are substantially an equal distance from the longitudinal axis 26 (FIG. 1) of the platform P and substantially tranverse thereto. Furthermore, the heel openings 22, 24 are preferably located in the upper layer 10 adjacent to where the arch 28 and heel 16 of the foot F join (FIG. 4).

The laminated platform P of the sandal S of the present invention is secured to the foot F by stirrup strap means A and toe securing means T therewith. The stirrup strap means A includes instep strap means 30, heel strap means 32, and loop or arch strap means 34. Each of such strap means 30, 32, 34 have respectively a first end 30a, 32a, 34a and a second end 30b, 32b, 34b. Preferably, the stirrup strap means A is formed of a protective, cushioned covering or tubing that is soft and preferably waterproof and preferably of a latex, surgical tubing, however, other materials may be used if so desired.

Connector means C is mounted with and is for joining together the instep strap means 30, heel strap means 32 and arch strap means 34. The connector means C includes connector 36 (FIGS. 5A, 5B). Preferably, the connector 36 is formed of a flexible polyethylene co-polymer, but suitable other materials may be used, and is of a three-pronged configuration having an instep prong 36a, a heel prong 36b and an arch prong 36c. The connector 36 may be of a substantially Y-configuration as shown in FIG. 5A or of a T-configuration (not shown) or of any other suitable, desired configuration. Preferably, the prongs 36a, 36b, 36c have a slightly greater diameter than that of the inside diameter of strap means A such that the appropriate end portion of such instep, heel, and arch strap means 30, 32, 34 may be forced or stretched onto the appropriate prongs 36a, 36b, 36c of the connector 36 for a tight, frictional engagement therebetween as discussed more fully hereinbelow.

The toe securing means T of the present invention includes an elongate portion 38 (FIGS. 6A, 6B, 6C) formed of legs 38a, 38b joined by an overlapped portion 38c. Each of the legs 38a, 38b has an end portion 38d, 38e, respectively. Securing portion 40 including portions 40a, 40b are preferably formed adjacent end portions 38d, 38e, in preferably a semi-circular configuration, however, any other suitable configuration may alternatively be used. Toe securing means T is preferably formed of a flexible, polyethylene copolymer and capable of being injection molded, however, may be formed of and by any other suitable material or method. It is preferred that the toe securing means T is of a single-piece construction with the elongate portion 38 and securing portion 40 being formed simultaneously. A toe cushioning 42 may be mounted with legs 38a, 38b of the elongate portion 38 for preventing chafing between toes 14 adjacent thereto. Preferably, the toe cushioning 42 is of a flexible, soft, waterproof material such as latex surgical tubing.

In practicing the method of this invention, the upper layer 10 is formed conforming to the shape of the sole of the foot F with toe opening 20 and heel openings 22, 24 formed therebetween the upper surface 10a and lower surface 10b of the upper layer 10. The toe securing means T is mounted with the upper layer 10 by overlapping the elongate portion 38 at overlapped portion 38c and inserting the overlapped portion 38c into toe opening 20 from the lower surface 10b of the first layer 10 and extending therethrough the toe opening 20 and therefrom the upper surface 10a of the upper layer 10 such that the legs 38a, 38b and the overlapped portion 38c extend above the upper surface 10a of the upper layer 10. Thereafter, toe cushioning 42 is inserted over the overlapped portion 38c and positioned upon the adjacent legs 38a, 38b as shown in FIGS. 2, 3 and 4.

The loop or arch strap means 34 is mounted with the first layer 10 by inserting first end 34a through heel opening 24 and second end 34b through heel opening 22 from the lower surface 10b, therethrough openings 24, 22, respectively, and extending therefrom upper surface 10a of the upper layer 10. It will be appreciated that the order in which the toe securing means T and arch strap means 34 is mounted with the upper layer 10 is of no consequence. Thus, the order of assembly may be alternated such that the arch strap means 34 may be mounted with the upper layer 10 prior to mounting the toe securing means T with the upper layer 10, or vice versa. However, it is important that the toe cushioning 42 be positioned about the toe securing means T after the toe securing means T is appropriately mounted within toe opening 20.

At this point, the instep strap means 30 is mounted with the toe securing means T by inserting one end, such as end 30a of the instep strap means 30 through the opening 38f (FIG. 6) formed by the overlapped portion 38c of the elongate portion 38 and approximately centering the toe securing means T on the instep strap means 30. Thereafter, interconnection of the stirrup strap means A is effectuated by connecting means C. More specifically, connector 36 is used to join the instep strap means 30 and arch strap means 34 and mount heel strap means 32 therewith. The order in which the respective instep, heel and arch strap means 30, 32, 34 are mounted with the connector prongs 36a, 36b, 36c, respectively, is immaterial. Thus, the end portions 30a, 32a, 34a of the instep strap means 30, heel strap means 32, arch strap means 34, respectively, are forced onto the connector prongs 36a, 36b, 36c, respectively. Inasmuch as the connector prongs 36a, 36b, 36c are of a slightly greater diameter than the inside diameter of the stirrup strap means A, the connector 36 frictionally engages such stirrup strap means A and permits minor adjustment of the relative lengths of the stirrup strap means A by means of movement of the ends of such stirrup strap means A along the prongs of the connector 36. More significant adjustments are accomplished by merely cutting off a portion of the appropriate stirrup strap means A with scissors or the like.

Thereafter, the lower layer 12, being formed to conform with the sole of the foot F in similar fashion as upper layer 10, is affixed to the upper layer 10 to finish the sandal. It will be appreciated that if it is desired that the laminated platform P of the sandal S of the present invention be of more than two layers, more layers may be added therebetween upper layer 10 and lower layer 12. The layers 10, 12 or any intermediate thereof may be bonded together by use of an appropriate adhesive substance, glue, or the like. Thereafter, the final sandal S may be refined by suitable finishing the laminated platform P by any machining process such as use of a belt and/or dish sander. Furthermore, the slits 18 may at this point be formed with the lower surface 12b of the lower layer 12.

In the use or operation of the sandal S of the present invention, it should be noted that most of the exposed components are easily replaceable without destroying the utility of the sandal S of the present invention. For example, the instep strap means 30 and heel strap means 32 are easily replaceable as is the toe cushioning 42, upon removal of the instep strap means 30. Furthermore, the loop or arch strap means 34 is removable even after the sandal S is in its fully assembled state without requiring the ungluing of the upper layer 10 and lower layer 12 of the laminated platform P. The removal of the loop or arch strap means 34 is accomplished by removing the connector 36 from ends 34a, 34b. Thereafter, a replacement arch strap means 34 (not shown) is forced into the existing arch strap means 34 as far as is possible. This is typically one-third to one-half of the overall length of the replacement arch strap means 34. Due to frictional resistance between the replacement arch strap means and the existing arch strap means 34, the existing arch strap means 34 may be pulled from the opposite-non-inserted end with a resultant new arch strap means being appropriately pulled into place and threaded into the old, worn arch strap means' previous position, without necessitating disassembly of the upper layer 10 and lower layer 12. Thereafter, the old, worn arch strap means is removed from the replacement arch strap means 34 and the new arch strap ends 34a, 34b are reconnected to the connector 36.

It should be noted that the loop or arch strap means 34, due to its particular positioning and location on the platform P, provides an arch for the foot to help facilitate proper arch support of the foot F.

As shown in FIG. 4, a further important feature of the toe securing means T is its flexible nature. The flexibility of the toe securing means T, particularly adjacent the end portions 38d, 38e and securing portions 40a, 40b, respectively, is significant to the durability of the sandal S. During normal wear of the sandal S of the present invention, typically such sandal S flexes about the toe end of the platform P upon the wearer taking a step with his foot F. The flex of the sandal S adjacent the toe end is accommodated by movement of the toe securing means T by the securing portions 40 flexing about an axis substantially perpendicular to the longitudinal axis 26 of the laminated platform P for preventing undue stress concentrations adjacent the toe end of the laminated platform P. Thus, when a step is taken, securing portions 40a and 40b can move angularly and laterally with respect to one another to accommodate such flexure in the sandal S, as do slits 18, thus preventing undue wear adjacent this portion of the sandal S due to the securing portion 40.

Inasmuch as the sandal S of the present invention is preferably constructed of vinyl foam, neoprene foam, polyethylene polymers, and latex surgical tubing, the sandal S of the present invention results in an extremely light-weight, waterproof sandal S. Furthermore, although the upper layer 10 of the platform P is initially of a substantially flat configuration of the upper surface 10a thereof, after a short period of use, the upper surface 10a of the upper layer 10 of the laminated platform P tends to compress in the areas adjacent the heel 16 and ball 44 of the foot F since the bulk of the weight of an individual is carried on these key points of the foot F. Thus, the upper surface 10a conforms to the elevational configuration of the sole of the foot F after a short period of use resulting in an extremely comfortable sandal S having a footprint-shaped compression set in the vinyl foam conforming substantially to the sole of the foot F. Still further, the stirrup strap means A being of the latex tubing prevents chafing of the foot F in any areas adjacent thereto when wearing the sandal S of the present invention.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.